The present invention pertains generally to covers such as shielding cans which are mounted on printed or etched circuit boards to isolate the electronic components thereunder from undesired interfering signals and specifically to an arrangement for conveniently and facilely mounting plural covers on the opposite surfaces of one or more planes.
As is well known, quite often metallic covers are placed over sensitive electronic components comprising a circuit board to provide shielding from undesired signals which might otherwise interfere with and degrade the circuit operation. With the continual striving for equipment miniaturization, comes a need to conserve as much space under the shielding cover as is practicable for accommodating electronic components which are more and more congested into smaller and smaller areas. Thus, whereas previously columns or posts formed separately or integrally with the shielding cover for providing a passageway to the mounting bolts which affix the cover to the board and/or positioning of the bolts irrespective of effective space utilization may have been unimportant considerations, the continuing reduction in space allocation for components warrants greater attention than heretofore in how the cover is to be affixed when mounted.
With the wide acceptance and copious utilization of circuit boards also comes a need for facilitating their testing when necessary, which in the case of shielding cans engenders mounting and removability convenience to afford ease of access to the circuit board components. Although such a concern may seem superficial and even trivial, it must be borne in mind that the number of boards to be tested during the course of some operation such as product assembly or subsequent troubleshooting may be considerable running into the hundreds or thousands. Consequently, even a few seconds savings in emplacing or removing a shielding can to access the components thereunder may generate substantial time and cost savings in required manpower. As may well be appreciated, the foregoing problems of space conservation under shielding cans and the ease with which they are mounted and removed, are greatly magnified when plural cans must be used for shielding opposite surfaces of one or more circuit boards used in combination.
Consequently, with the foregoing in mind, it is a primary object of the present invention to provide a new and improved arrangement for mounting plural covers on the opposite surfaces of one or more planes.
It is a further object of the present invention to provide such an arrangement which minimally detracts from the allotted space under the covers while affording a great degree of flexibility and convenience in mounting and removing the covers to access the components thereunder.
These, as well as other objects and the means by which they are achieved through the present invention, may best be appreciated by referring to the Detailed Description of the Invention which follows hereinafter together with the appended drawings.